Measures of oral health-related quality of life in patients with bone graft and implant prosthetic rehabilitation at the anterior of mandible/maxilla among young and middle-aged adults: a retrospective pilot study

Tooth loss mainly occurs due to dental caries and periodontal disease. Previous reports have mentioned that an increasing number of missing teeth negatively affects oral health-related quality of life (OHRQOL) [1]. Clinical studies, including in dentistry and oral and maxillofacial surgery, have mainly focused on the development of diagnoses, surgical results, and surgical procedures. The World Health Organization provides the following definition of health: “a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity”. Recently, the health-related quality of life (HRQOL) of patients has increasingly caught the attention of medical professionals. Previous reports have found associations between rheumatoid arthritis, cardiovascular disorders, diabetes, and HRQOL [2, 3]. Some reports have also suggested a relationship between HRQOL and OHRQOL [4, 5], and attention has been focused on the relationship between OHRQOL and various oral diseases, such as periodontal disease [6], dental caries [7], and temporomandibular disorder [8]. Further, tooth loss is a dental disease that significantly affects OHRQOL [9]. Davis et al. mentioned that 45% of participants in their study felt unprepared for the effects of losing teeth [10]. They also reported that those patients were reluctant to accept the loss of teeth and were less self-confident as a result [11]. With tooth loss, the impact of anterior tooth loss on OHRQOL is particularly large. Imam et al. revealed that anterior missing teeth in particular had a strong impact on patients, exerting effects in terms of pain, physical disability, and psychosocial dimensions [12]. Furthermore, other reports have mentioned that patients with ≤ 12 missing teeth, but including some anterior teeth, were more likely to present with higher OHIP scores than those with ≤ 12 missing teeth, but no missing anterior teeth [13]. With advances in oral hygiene, such as brushing with fluoridated toothpaste, avoidance of cigarette smoking, and regular preventive dental check-ups [14] the prevalence of tooth loss has been on the decline in recent decades. The estimated global prevalence of total tooth loss decreased from 4.3% in 1990 to 4.1% in 2015 [15]. However, in patients with mandibular or maxillary tumors [16, 17], maxillofacial injuries, [18] or cleft lip and palate (CLP) [19], tooth loss is common even among young and middle-aged patients. In such cases, jawbone reconstruction using free vascularized bone grafts, iliac particulate cancellous bone marrow (PCBM) grafts, or bone block (BB) grafts are often performed to improve facial contours and allow the insertion of a dental implant. In recent years, this comprehensive therapeutic strategy has become widely applied and implant survival rates for these patients have reached an ideal level [20‐22]. However, limited information has been accumulated regarding how this strategy affects the OHRQOL of patients.

The aim of this study was to evaluate the clinical outcomes of dental implant prosthetic rehabilitation after bone graft to the anterior mandible/maxilla based on OHRQOL, with a focus on young and middle-aged patients.

The present study aimed to evaluate the influence of bone graft and dental implant prosthetic rehabilitation at the anterior mandible/maxilla on OHRQOL, with a focus on young and middle-aged patients. Our previous report revealed that in cases of malignancy, chewing function was apparently inhibited after tumor resection [25, 26]. These results were probably attributable to muscle tissue resection, jawbone resection, and tooth loss. Maeda et al. mentioned that masticatory function is controlled by various muscle movements [27]. In fact, other reports have investigated the electromyographic activity in patients who underwent marginal resection and found a difference in maximum voluntary clenching between the defect and non-defect sides [28]. On the other hand, in cases without malignancy, resection of muscle tissue is rare. Our previous report thus revealed no significant impairment in chewing function according to the　chewing function questionnaire [25]. Such trends are similar to the present results (Fig. 2), because patients in this study showed a relatively high number of remaining teeth and preserved muscle tissue (Tables 2, 3), so they could successfully chew almost all ingredients listed on the chewing function questionnaire before completion of bone graft and implant prosthetic rehabilitation. According to the results of OHIP-14, Physical disability (which consists of unsatisfactory diet and interrupted meals) had a relatively lower score even before implant prosthetic rehabilitation (Table 4). Social disability (which consists of irritable and difficulty performing daily tasks) was also relatively unrelated to teeth loss, and tendencies toward improvement following bone graft and implant prosthesis could be observed.

In contrast, we confirmed that patients in this study suffered from Functional limitation (before: 2.81 ± 0.98), Psychological discomfort (before: 3.18 ± 2.14), and Psychological disability (before: 2.82 ± 1.72). Tooth loss can adversely affect pronunciation, and indeed, a previous study reported that speech ability was significantly lower among individuals with fewer teeth [29]. In fact, none of the patients in the present study scored 0 (“never”) in the Functional limitation domain, especially for trouble pronouncing words. Furthermore, this study involved patients aged between 17 and 60 years, who were usually still employed or in school life, and presumably had many opportunities to come into contact with various other people. These backgrounds are also assumed to be one factor that led to psychological discomfort and psychological disability. Results from the OHIP-14 assessment apparently showed that implant prosthetic rehabilitation significantly improved scores in these domains. Although patients in this study had to undergo several surgical procedures (e.g., tumor resection, bone graft, and implant surgery), the fact that this series of treatments contributed to the improvement of OHRQOL was considered indicative of the legitimacy of the treatment.

We should note that the present study had several limitations. A key potential weakness of this study was the small sample size. To add to the evidence produced in our study, further longitudinal studies of larger numbers of participants are needed to strengthen and confirm our findings. A second limitation was that this study was based on subjective examinations. In the future, evaluations will need to be based on relationships with objective evaluations. Further, medium- and long-term observations will be necessary regarding relationships between implant survival and OHRQOL.

The results suggest that dental implant prosthetic rehabilitation contributed to the improvement of OHRQOL. The results of this study will be of benefit to both patients and medical professionals in terms of treatment planning and obtaining informed consent.